Celestia Forums

Do you know what is the largest Earth texture available from the net?
Most of you would probably say that the answer is 45k (?) texture that's
used to build most of our current Earth VTs. Well, you would be wrong.
The largest Earth texture that has more or less complete coverage of
continental part of the Earth (including islands) is a 2048k 'texture'
available through http://www.terraserver.com (GlobalExplorer International 15m).
The problem with Terraserver is that it's a pain to use. You can only
generate one 500x500pix image at the time (with their logo and copyright
notice) and you can't even save it to disk from IE. Also, not all of the
pictures are at the exactly the same scale so you would have to rescale
most of the tiles in the the Photoshop (calculating the correct scale
from the info found on the website is quite complicated and time consuming).
You would probably spend more then a few hours building a 4 picture mosaic
neaded for just one level10 tile!
That's why I am working on a series of perl scripts that would do all
that automaticaly. You would only say what part of the world you would
like to make the VT of (for example, you country or state) and after
few hours you would get a finished level10 (or even level12) texture of
that area. The scripts are very complex but they do work! I have just
finished the test build of Croatia (480 level10 tiles) and here are the
results (as far as I know this is the largest level10 VT and it is just
a quick 'test' build):

The 32k VT:


My 1024k:


Things are not yet perfect. Currently the scripts build only the level10
of the virtual texture also ignoring the available lower-level tiles
(the level10 images should be 'pasted' on the enlarged lower-level tile).

There are also 2 big problems for the most people. The scripts work (and
will always work) _only_ in Linux. The other problem is copyright related.
Even though anyone can download these images from Terraserver, you can't
legally redistribute modified copys. That means that I (or anyone else)
can't build a VT and send it to you. You nead to run my script yourself
(which you can do legally).

Anyway, what do you think? Anyone interested?

Sounds interesting, although I personally do not like to get involved too much with such commercial companies.

I cannot see whatsoever, why your perl scripts should only work in (native) Linux. I am using both native Linux and Cygwin within Windows XP. All my scripts work perfectly under Cygwin (Linux). There is also a native Perl installation for XP, of course. My 'virtualtex' VT-tiling shell script, using fancy bash or zsh syntax work also without problems under Cygwin. All my quite non-trivial perl scripts for Celestia work under Windows.

Bye Fridger

Hi t00fri! I was just about to email you and ask if you could send me your virtualtex program as
I need it for DDS->PNG cnversion Could you, pretty please?
My email is: dsvilko A T fizika.org

As for getting involved with big companys... from all the available data (legal stuff) from their
website, what my script is doing is completely legal. I can't distribute the final textures but
I can distribute my scripta and anyone can make their own textures.

As for running the scripts under Windows... it's not just perl. I also use ImageMagick, wget and Sodipodi and I don't know it they are all available for Cygwin.

Bye!

Sounds good so far

maxim

dos wrote:Hi t00fri! I was just about to email you and ask if you could send me your virtualtex program as
I need it for DDS->PNG cnversion Could you, pretty please?
My email is: dsvilko A T fizika.org

As for getting involved with big companys... from all the available data (legal stuff) from their
website, what my script is doing is completely legal. I can't distribute the final textures but
I can distribute my scripta and anyone can make their own textures.

As for running the scripts under Windows... it's not just perl. I also use ImageMagick, wget and Sodipodi and I don't know it they are all available for Cygwin.

Bye!

Dos,

of course, I run ImageMagick both under Windows and Cygwin. You may use the native XP ImageMagic and make its PATH known under Cygwin. Then it works beautifully and fast under both. 'Wget' also works of course in Cygwin. Sodipodi is not really necessary. I never cared about it.

Here is the URL for downloading the latest 'virtualtex'

http://www.shatters.net/~t00fri/virtualtex

Bye Fridger

Here is the URL for downloading the latest 'virtualtex'

That's not it. Sorry, I thought that's what it was called. I was thinking of the (c?) program that can convert DDS image to PNG image and runs under linux.

dos wrote:

Here is the URL for downloading the latest 'virtualtex'

That's not it. Sorry, I thought that's what it was called. I was thinking of the (c?) program that can convert DDS image to PNG image and runs under linux.

Yes I wrote that, too. But I have not yet made a 'distribution' of it. So I make it available only to "close friends" for now. To compile it, one has to first install the latest CVS DevIL libs etc. I have no time to deal with people's NOGO complaints. This is strictly 'developer level' stuff.

I would /never/ convert lossy DXTx format into something else. It's bound to get pretty bad. My tool is called 'texconvert'. It is mainy meant to convert gigantic textures from PNG, for example to DXTx, but not the other way around. Of course, technically, texconvert also can do it.

Bye Fridger

dos your idea sounds very interesting. Once you get to state where you are looking for some beta testers, I would love to take part. I do most of my work on Mac OS X and Linux, but also have access to Windows boxes as well.

I've always wanted to do some VT of my home town as well as some of the national parks and other vacation spots that I've visited, but seeing as how I'm graphically challenged that has never been an option.

I for one am looking forward to what you you come up with.

Hi Fridger!

Yes I wrote that, too. But I have not yet made a 'distribution' of it. So I make it available only to "close friends" for now. To compile it, one has to first install the latest CVS DevIL libs etc. I have no time to deal with people's NOGO complaints. This is strictly 'developer level' stuff.

That's all right. I have installed the latest CVS DevIL (pretty smooth install) and found out
that there is a sample program that can do what I nead (DDS->PNG->DDS conversion).

I would /never/ convert lossy DXTx format into something else. It's bound to get
pretty bad.

Well, I have no choice. If I want to integrate my VT into a existing DDS VT than I have to
convert DDS tiles to PNG, strach them to level10 and then pase my new level 10 tiles.
As I am enlarging the level5 tiles far beond their native resolution, it doesen't matter
if I lose a few details along the way.

Anyway, I have made some progress. In fact, the scripts are more or less finished. I have
made a level6-level10 VT of Croatia (770 tiles, 110MB) that's perfectly integrated into a 32k
VT. The scripts are still not very user friendly but they do work.

Bye, DoS

Hi Dos,

dos wrote:Hi Fridger!

Yes I wrote that, too. But I have not yet made a 'distribution' of it. So I make it available only to "close friends" for now. To compile it, one has to first install the latest CVS DevIL libs etc. I have no time to deal with people's NOGO complaints. This is strictly 'developer level' stuff.

That's all right. I have installed the latest CVS DevIL (pretty smooth install) and found out
that there is a sample program that can do what I nead (DDS->PNG->DDS conversion).

That's good and also illustrates that you know your 'way' pretty well in these matters. In the last CVS version that I installed there were still a number of buggies.
Have an eye on whether the various mipmaps are actually stored in the DDS encoded file. It may say so, but still no mipmaps were stored in my case. They are quite essential, of course.

The DevIL libs are very fast and produce good quality DXTx code.

...
Anyway, I have made some progress. In fact, the scripts are more or less finished. I have
made a level6-level10 VT of Croatia (770 tiles, 110MB) that's perfectly integrated into a 32k
VT. The scripts are still not very user friendly but they do work.

Bye, DoS

If you like, I might well help a bit with testing. At night, my dreams are in 'Perl' , you know ...Also I have a fast 375KByte/sec ADSL line. So downloading multi GB-sized files is no problem whatsoever for me.
...And I am a Celestia developer, knowing quite a bit about textures and all that .

Bye Fridger

Dos,

Another source of high resolution imagery is via the NASA Worldwind Project
http://worldwind.arc.nasa.gov/

I've posted in the past on converting WorldWind caches into Celestia VT's.

Ideally the ability to pull Earth tiles directly from servers can be worked into Celestia but first it is necessary to have access to deeper levels. IIRC, the .3m resolution data available from various sources works out to level17. Chris has made some progress on that front but I assume he has not found an adequate solution yet for going that deep.

cheers,
Walton